The objective for the coming year is to more carefully analyze the bactericidal (anti-gonococcal) capacity of human neutrophil and monocyte/macrophage phagolysosomes. The specific aims are 1) to optimize a system to measure anti-bacterial activity of isolated phagolysosomes and their subcellular fractions, 2) to correlate in vitro biochemical and structural observations related to bactericidal events with in situ phenomena, i.e. with events occurring within phagolysosomes of phagocytising leukocytes, 3) to correlate lysosomal bactericidal activity with phagolysosomal bactericidal activity, and 4) to carefully quantitate initial events (first seconds or minutes) occurring within phagolysosomes that are responsible for bacterial death. Phagolysosomes will be isolated on density gradients from homogenates of leukocytes that have phagocytized bouyant particles (latex or oil) that have been opsonized with various biologically active materials. Analytical techniques to be used include polyacrylamide gel electrophoresis of phagolysosomal and gonococcal proteins, photometric and fluorometric assays of numerous enzymes, classical bactericidal and phagocytic bactericidal assays, chemiluminescence, radiolabel experiments, and chromatograhic separation of various leukocyte or bacterial components.